The present invention relates to medical devices for inserting medical instruments into a patient""s blood vessel. In particular, the present invention relates to medical devices having a sharpened flexible needle for inserting a medical instrument, such as a pacemaker lead, into a patient""s blood vessel. The flexible needle pierces the patient to provide vascular access. After vascular access is established, the flexible needle is retracted into a flexible sheath and catheter that surround the needle. The flexible needle remains inside the sheath as the sheath and catheter are bent into alignment with the blood vessel and advanced into the blood vessel. Once the catheter is set properly within the blood vessel, the sheath and retracted needle are pulled out from the patient leaving the catheter within the patient""s blood vessel. A pacemaker lead or other medical instrument is inserted into the catheter and advanced through the catheter into the patient""s body. The catheter is then removed.
The insertion of pacemaker leads and other elements into the heart region requires piercing the skin with a needle device to provide access to blood vessels. The process for inserting pacemaker leads into the heart begins with the insertion of a needle set into the upper chest. The needle set, which includes a sharpened needle surrounded by a dilator sheath and a catheter, is inserted into a vein in the upper chest, such as the subclavian vein. When the needle tip has accessed the vein, blood flows out the back of the device. Consequently, a syringe or other blood collection device is attached to the needle set to prevent the blood flow from leaking out the device onto the medical professional.
The sharpened needle is typically a rigid needle. As a result, the needle set is relatively stiff. To facilitate insertion of the pacemaker lead, the needle set must be carefully turned while it is in the subclavian vein so that the passage in the needle set is aligned with the axis of the blood vessel. After alignment is achieved, the syringe is removed from the rear end of the device. A guidewire is then fed through the open rear end of the device and needle set into the subclavian vein. The guidewire is advanced down the subclavian vein to a position above the right atrium of the heart. The needle is pulled from the needle set and the dilator sheath and catheter are pushed down the guidewire and positioned above the right atrium of the heart. The guidewire is removed, followed by the dilator sheath, so that only the catheter remains in place in the patient. A pacemaker lead is fed into the catheter and threaded into the right atrium of the heart. Once the lead is in proper position, the catheter is removed.
The foregoing procedure involves a number of steps that are labor intensive. In particular, the procedure includes insertion and removal of many separate components. In addition to being labor intensive, the procedure poses safety risks to the medical professional. When the needle is removed from the needle set, it is contaminated. The handling of such used needles poses a risk of transmission of various pathogens, including human immunodeficiency virus (HIV), due to inadvertent needle sticks.
Based on the foregoing, the present invention provides a medial device that allows a safer and more simplified method for percutaneous insertion of medical instruments, such as pacemaker leads. The device is intended for insertion into any medium or large diameter blood vessel accessible through the skin. For purposes of this disclosure, the device will be discussed as it is used in the insertion of pacemaker leads. The device includes a sharpened flexible needle surrounded by a dilator sheath, both of which extend from a housing. A catheter is detachably connected to the front end of the housing over the needle and dilator sheath. A flashback chamber is fixed to the rear end of the housing.
When the flexible needle is inserted, access to the vein is verified by the appearance of blood in the flash chamber. Once the vein is accessed, the needle is retracted into the dilator sheath where it is safely enclosed for the remainder of the procedure. The flexible dilator sheath and catheter are deformed into alignment with the axis of the subclavian vein and advanced down the subclavian vein to a position above the right atrium of the heart. Since the needle is flexible, it can bend with the dilator sheath and catheter and need not be removed during the insertion procedure. The housing, dilator sheath and retracted needle are pulled out of the patient, leaving the catheter in the patient. The dilator sheath encloses the contaminated needle so that the sheath and needle can be safely discarded with minimal risk of accidental needle sticks. A pacemaker lead is then fed through the catheter in the subclavian vein and advanced into the heart. Once the lead is in place, the catheter is removed from the patient, and the lead is connected to a pacemaker device.